Many organic materials are subject to degradation due to fungal or bacterial attack. For example, wood is one of the best structural materials for the construction of buildings because of its strength, ease of processing, and relatively low cost, but wood has one serious drawback in that it is susceptible to discoloration and decay by wood destroying fungi. While there are a number of materials that will control bacteria and fungi, many are highly toxic to man. This invention is directed to compounds that are both effective biocides and also of low toxicity to man.